Wrap-Up Questions

Questions 1-4 modified From Online Open Genetics (Nickle and Barrette-Ng)[1].

1. Wiry hair (W) is dominant to smooth hair (w) in dogs.

  1. If you cross a homozygous, wiry-haired dog with a smooth-haired dog, what will be the genotype and phenotype of the F1 generation?
  2. If two dogs from the F1 generation mated, what would be the most likely ratio of hairphenotypes among their progeny?
  3. When two wiry-haired Ww dogs actually mated, they had a litter of three puppies, which all had smooth hair. How do you explain this observation?
  4. Someone left a wiry-haired dog on your doorstep. Without extracting DNA, what would be a way to determine the genotype of this dog?

2. An important part of Mendel’s experiments was the use of homozygous lines as parents for his crosses. How did he know they were homozygous, and why was the use of the lines important?

3. Does equal segregation of alleles into daughter cells happen during mitosis, meiosis, or both?

4. A rare dominant mutation causes a neurological disease that appears late in life in all people that carry the mutation. If a father has this disease, what is the probability that his daughter will also have the disease?

5. In dogs, long hair is dominant to short and black fur is dominant to brown. A long-haired black dog and a long-hair brown dog have a short-haired brown puppy. Give the genotypes for both parents and the puppy.

6. Individuals with genotype AaBbCc and AaBBcc were crossed. What is the likelihood that the first offspring will have all three dominant traits?

Science and Society

7. Although science is meant to be objective, a scientist’s identity and background strongly informs the questions that are asked and the way data is analyzed.  Mendel investigated hybrids because he came from a community where that was really important.  He analyzed biological data with math, because he learned to do that from studies in chemistry/physics.  What parts of your identity drive your scientific curiosity? What other strengths do you bring to your studies in biology and genetics?

  1. Nickle and Barrette-Ng. Open Online Genetics. in Open Online Genetics (2016).


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